Question 26

802.1x should be enabled to allow network connections only after authentication.

802.1x is a network access control protocol that provides an authentication mechanism for devices wishing to connect to a network, ensuring that only authorized users can gain access.

A) Port security

Port security is a feature that restricts the number of MAC addresses that can be learned on a port, and while it can prevent unauthorized devices from connecting, it does not require authentication before allowing network access. Therefore, it does not meet the requirement of allowing connections only after authentication.

B) 802.1x

802.1x is designed specifically to provide port-based network access control, requiring devices to authenticate before they can communicate on the network. This feature directly addresses the need for increasing security through authentication, making it the best choice for the scenario described.

C) MAC filtering

MAC filtering allows or denies devices access to the network based on their MAC addresses. However, it does not actually require authentication of users; it simply filters based on the hardware address, which can be spoofed. Thus, it does not fulfill the requirement for secure authentication.

D) Access control list

Access control lists (ACLs) are used to permit or deny traffic through routers and switches based on specified criteria. While useful for controlling network traffic, ACLs do not provide the authentication mechanism needed to ensure that only authorized users can connect to the network.

Conclusion

In this context, enabling 802.1x is essential for ensuring that only authenticated users can access the network, directly addressing the security requirement posed by the network engineer. Other options, including port security, MAC filtering, and ACLs, do not provide the necessary authentication step and therefore do not meet the specified need for increased security.